Welcome To the Hoffman Amplifiers Forum

September 07, 2025, 01:30:28 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: ampeg reverbrocket 2 ps voltage too high???  (Read 2616 times)

0 Members and 1 Guest are viewing this topic.

Offline mikhett

  • Level 1
  • *
  • Posts: 41
Hoffman Amps Forum image
ampeg reverbrocket 2 ps voltage too high???
« on: March 27, 2011, 07:40:15 pm »
I just finished rebuilding a 67 ampeg rr2 amp.this is the one with a 12ax7,6u10,7199 and a pair of 7591s.Im getting 380 volts at the first 2 filter caps then 340 at cap"C" and 300volts at cap "D".There should only be 200 volts at d .It feeds the plates of the 12ax7 and one side of the 6u10.I measured the 1k,10k and 470 ohm ps resistors and they check out right.im checking the wiring in the ps section but everything seems right.this rebuild was a nightmare as i used a 43 pin 17 inch turret board as the ampeg is loaded with components due to the reverb.HELP! Thanks Mike

Offline PRR

  • Level 5
  • *******
  • Posts: 17082
  • Maine USA
Hoffman Amps Forum image
Re: ampeg reverbrocket 2 ps voltage too high???
« Reply #1 on: March 27, 2011, 08:58:06 pm »
> There should only be 200 volts at d .

That is probably incorrect.

300V-330V seem more likely.

How does it play?

Offline mikhett

  • Level 1
  • *
  • Posts: 41
Hoffman Amps Forum image
Re: ampeg reverbrocket 2 ps voltage too high???
« Reply #2 on: March 28, 2011, 07:41:03 am »
Im checking with tubes removed,and dummy speaker load before installing tubes.

Offline LooseChange

  • SMG
  • Level 4
  • *****
  • Posts: 3511
  • Keep it greasy so it goes down easy.
    • Fix Your Darn Amps
Hoffman Amps Forum image
Re: ampeg reverbrocket 2 ps voltage too high???
« Reply #3 on: March 28, 2011, 07:51:55 am »
All voltages will be high with no tubes... Need tubes to check voltages.
Dummy speaker load not needed with NO tubes.
Call me Dan
www.fydamps.com

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: ampeg reverbrocket 2 ps voltage too high???
« Reply #4 on: March 28, 2011, 07:54:29 am »
Quote
Im checking with tubes removed
In that case, all plate voltages will be high because there is no load on the power supply. No plate current is flowing, so no voltage drops across the B+ nodes or plate resistors.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program


password